Electric motor frame having coolant system incorporated therein



Sept. 23, 1952 HAYES 2,611,798

ELECTRIC MOTOR FRAME HAVING COOLANT SYSTEM INCORPORATED THEREIN Filed Dec. 22, 1950 2 SHEETSSHEET 1 INVENTOR. ROBERT E. HAYES Sept. 23, 1952 HAYES 2,611,798

ELECTRIC MOTOR FRAME HAVING COOLANT SYSTEM INCORPORATED THEREIN Filed Dec. 22, 1950 2 SHEETS-SHEET 2 INVENTOR. ROBERT R. HAYES Patented Sept. 23, 1952 ELECTRIC MOTOR FRAME HAVING COOL- ANT SYSTEM INCORPORATED THEREIN Robert R. Hayes, Cleveland, Ohio, assig'nor to The Reliance Electric & Engineering 00., a corporation of Ohio Application December 22, 1950, Serial No. 202,210

4 Claims.

My invention relates in general to frames for electric motors and more in particular to a frame or housing which has incorporated therein passages for a cooling system for cooling the electric motor.

This is a continuation-in-part of original application, Serial No. 126,354, filed November 9, 1949, by the same applicant.

Many methods have been devised and much experimentation has been done on the cooling of electric motors, and especially electric motors of the explosionproof type. I have devised a housing which can be readily cast with the ribs on the outside thereof and a shell enclosing this housing and engaging these ribs to cause the space between the ribs to serve as cooling passages for the flow of a coolant throughout the housing. This combination of a cast inner frame or housing and a shell plate, which may be welded to the cast inner frame or inner housing, is a simple but effective cooling jacket which covers the marginal portion of the cast housing for either A. C. or D. C. machines. The cast inner frame or housing has channels or ribs molded on its outer periphery in such manner as to form a continuous coolant passage from end to end and covering the outside of the inner frame or housing. Although this construction is particularly suited for cylindrical inner housings or 'frames, I wish it readily understood that the teachings of my invention can be applied to frames and housings of other shapes without departing from the spirit and scope of my invention.

Keeping in mind the problem involved; that is, providing a cooling system in a cast housing for electric machines so that the rating or power of the machine can be increased without increasingthe size of the machine, I have as one of the objects of my invention the provision of a cooling system for an electric motor or other electric machine.

Another object of my invention is to construct a housing for an electric motor from a hollow member having ribs extending lengthwise thereof and on the outside surface thereof with these ribs enclosed by a shell to provide a continuous T cooling passage for the flow of a coolant throughout the frame or housing.

Another object of my invention is to provide a cooling system for an electric machine wherein the coolant is in intimate contact with either the magnetic section of a D. C. machine or the inner housing or frame of an A. C. machine which in turn is in contact with the internal parts of the machine to conduct the heat therefrom.

Another object of my invention is to provide a cooling system for explosionproof motors having a cast housing.

A further object of my invention is to provide a cast housing with ribs extending lengthwise thereof and integrally cast therewith by having certain surfaces of the ribs disposed substantially parallel with each other.

A still further object of my invention is to provide a cast housing with ribs extending longitudinally thereof on the outside surface with the surfaces of the ribs aligned whereby the cast housing can be removed from a mold without damaging the mold.

Another object of my invention is to provide a cast cylindrical housing with ribs extending longitudinally thereof on the outside surface with the surfaces of the ribs aligned whereby the cast cylindrical housing can be removed from a mold without damaging the mold.

Other objects and a fuller understanding of my invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings in which:

Figure 1 is a side view of a motor frame embodying the features of my invention, with part thereof being shown in section to particularly illustrate the parts thereof;

Figure 2 is an end view of the machine illustrated in Figure l with part thereof broken away to particularly illustrate the features of my invention; V

Figure 3 is a slightly enlarged side view of the inner cast housing illustrating the ribs extending longitudinally on the outer surface thereof and with the lower part shown in cross-section;

Fig. 4 is a sectional view taken along the line 4-4 of Figure 3; and

Figure 5 is a diagrammatical illustration of the path of the coolant in the coolant system illustrated in Figures 1, 2, 3 and 4, and which is incorporated in the motor frame or housing.

I have illustrated in Figure l the features of my invention as being used in connection with electric motor of the explosionproof type. However, it is understood that coolant system and the housing described herein can be used in other electrical machinery of A. C. or D. C. design, such as, for example, generators and motors.

The motor illustrated in Figure 1 comprises in general a frame 10 having a stator l l mounted therein and having end covers I2 and [3 which support a rotor M. The stator H and the rotor It may be of any suitable construction as is generally used in electrical machinery.

The frame ID is constructed from an inner housing 20 and a shell 2| which encloses the housing 20. This inner housing 20 is preferably constructed of casting so that it will provide explosionproof housing of a unitary integral structure. The general construction of the inner housing 29 which isformed by casting, is best illustrated in Figures 3 and 4.

In this particular instance, the inner housing 20 is of cylindrical construction and has an outer surface 22. A plurality of ribs 23 are integrally cast in the inner housing 28 and extend longitudinally of the housing and along the outer surface 22 thereof. An end rib portion 24 is spaced from the ribs 23 on one end of the housing 20 and an end rib portion 25 is spaced from the ribs 23 on the other end of the housmg.

Figure 4 best illustrates the end rib portions 24 and 25 integrally engaging the ends of the housing 23- so that a passage is formed extending between the ribs and around the housing. The ribs 23 and the rib portions 24= and 25 are raised with respect tothe outer surface 22. The ribs 23 join the main body portion of the cast housing 26 throughout a major portion of the length thereof. Each of the ribs 23 is provided with side surfaces 2'! and 28 ,which merge with or intersect the-outer surface of the inner housing, 20 anda shell engaging surface 29.

In Figure 4 of the drawings, I have also diagrammatically illustrated the two'parts of a mold in which the inner housing 28 may be cast. The side surfaces 21 and 28 along with the shell engaging surrace 29 of the ribs are aligned so that the-two parts of the mold may be separated and theinner housing 23 removed without damaging the mold. These surfaces can be described as being substantially parallel respectively with each other with the surfaces facing their respective part of the mold, or being disposed in substantially the plane of line of movement of that part of the mold away from the castinner housing 201 i The side surfaces 21 and 28 of the ribs are curved" into the outer surface 22 of the'cast housing 20 and the ends of the ribs are curved so that there are no sharp edges or sharp corners on the casting. This curving of the surface provides a much stronger casting as well as pre venting the pocketing or eddying cf coolant flowing in the space or passage between the ribs.

After the inner housing 23 has been formed as a unitary casting with the ribs 23 and the end rib portions 24' and 25, the inner housing is enclosed in the'shell 2! as is illustrated in Figure 1. This shell 2-! engages the shell engaging surfaces 29 of the ribs 23 as well as engaging the end rib portions 24 and 25. I have found it preferable to weld the shell on to the end rib portions 24 and" 25 asindicated by the weld 30 and 3! in Figure 1. These welds 30 and 3| tightly fasten the ends of the shell onto their respective rib portions 24 and 25 to make a sealedcoolant enclosure. Thus, the weld 30 may be considered to encircle one end portion of the cast housing 28 and the weld 3| to encircle theother end portion thereof.

In this particular instance, I have used a fiat sheet which is pressed around the inner housing 20' for the shell 2!. found it advisable to weld the edges of the shell together by a weld 32 before the shell is placed around the inner housing 20. This weld 32 extends longitudinally of the shell 21 and thus the inner housing- 201 It is understood, however, that In actual practice I have b 4 although I have used the flat sheet for the shell 2 I, seamless tubing or other similar members can be used.

The shell 2! cooperates with the ribs 23 and the outer surface 22 to form the coolant passages which extend longitudinally on the outer surface 22 of the cast housing 20. These passages or spaces between the ribs 23 cover a large part of the surface area of the inner housing 20 so that coolant flowing through the passages will cool the housing 20 and thus the frame I!) of the motor to provide a cooler running motor.

In Figure 5, I have illustrated a diagrammatical View of the coolant passages showing that the coolant flows between the ribs 23 and around the inner housing 20. Water enters the fluid passages between the ribs through an inlet and travels in the direction of the arrows until it reaches the outlet. The inlet in this particular instance is provided by a tapped opening 34 in the end of the inner housing 20, as is illustrated in Figure 2. The outlet is similarly shown by tapped opening 35 spaced from the opening 34 and in the inner housing 20.

Any coolant entering the inlet will travel between the ribs inthe coolant passages in a general direction longitudinally of the housing or frame until it reaches the outlet. Any heat generated in the motor will travel into the housing H3 and thus be picked up by the coolant. With the system herein described, the coolant flows in coolant passages in the frame constructed from a casting and a shell welded to the casting. An explosionproof motor having a cast frame with my coolant system therein has a higher rating than other type motors without increasing the size of the motor.

Although my invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. In a housing for an electric motor, a unitary hollow cylindrical member formed by casting and having an outer surface,- a plurality of raised ribs spaced about said outer' surface and extending longitudinally of said cylindrical mem ber, said ribs integrally joining said cylindrical member throughout at least a major portion of the length thereof, each of said ribs having side surfaces'curving into said outer surface with the said side surfaces of all the ribs disposed in substantially parallel planes, a raised first end portion integrally joined with said cylindrical member on one end thereof and spaced from the ends of the ribs, a raised second end portion integrally joined with said cylindrical member on the other end thereof and spaced from the ends of the ribs, said ribs and said end portions being formed on the outer surface of said cylindrical member by casting the same as a single unit.

2. In a housing for an electric motor, a unitary hollow cylindrical member formed by casting and having an outer surface, a plurality of raised ribs spaced about said outer surface and extending longitudinally of said cylindrical member, said ribs integrally joining said cylindrical member throughout at least a major portion of the length thereof, each of said ribs having side surfaces curving into said outer surface with the said side surfaces of all the ribs disposed in substantially parallel planes, a raised first end portign integrally joined with said cylindrical member on one end thereof and spaced from the ends of the ribs, a raised second end portion integrally joined with said cylindrical member on the other end thereof and spaced from the ends of the ribs, said ribs and said end portions being formed on the outer surface of said cylindrical member by casting the same as a single unit, a coolant inlet,

said ribs integrally joining said cylindrical member throughout at least a major portion of the length thereof, each of said ribs having side surfaces curving into said outer surface with the said side surfaces of all the ribs disposed in substantially parallel planes extending parallel to the longitudinal axis of the housing, .a raised first end portion integrally joined with said cylindrical member on one end thereof and spaced from the ends of the ribs, a raised second end portion integrally joined with said cylindrical member on the other end thereof and spaced from the ends of the ribs, said ribs and said end portions being formed on the outer surface of said cylindrical member by casting the same as a single unit.

4. In a housing for an electric motor, a unitary hollow cylindrical member formed by casting and having an outer surface, a plurality of raised ribs spaced about said outer surface and extending longitudinally of said cylindrical member, said ribs integrally joining said cylindrical member throughout at least a major portion of the length thereof, each of said ribs having side surfaces curving into said outer surface with the said side surfaces of all the ribs disposed in substantially parallel planes extending parallel to the longitudinal axis of the housing, a raised first end portion integrally joined with said cylindrical member on one end thereof and spaced from the 'ends of the ribs, a raised second end portion integrally joined with said cylindrical member on the other end thereof and spaced from the ends of the ribs, said ribs and said end portions being formed on the outer surface of said cylin drical member by casting the same as a single unit, a coolant inlet, a coolant outlet, and a shell engaging said ribs and said end portions thereby providing a continuous coolant passage along the major part of the said outer surface of said hollow member from said coolant inlet to said coolant outlet.

ROBERT R. HAYES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 716,278 Reist Dec. 16, 1902 771,468 Falk Oct. 4, 1904 914,046 Hissink Mar. 2, 1909 OTHER REFERENCES Pattern Making, by Homer, 3rd edition, published 1902 by Crosby, Lockwood and Son, London, pages 164-166. 

